1. Field of the Invention
The present invention relates to a device for transporting a sheet to be printed in a printer, with a carriage which is designed for receiving the sheet and which can be displaced on a fixed stand perpendicularly to the line direction between a starting position for inserting and removing the sheet and an end position moved into the printer, with a drive device for the carriage and with a releasable clamping device for clamping the sheet, which clamping device is arranged on the carriage and is provided with means for its own release which are actuated by actuating means coming into engagement with the carriage in the starting position of the latter.
2. Description of the Related Art
Such a device is known from European Patent Document EP 0,080,723 B1. Racks, which engage with toothed segments that can be pivoted using a motor, are provided on the carriage. Provided as a clamping device is a leaf spring, one end of which is fastened to the carriage and the free end of which bears under pre-stress on the carriage. Arranged on the leaf spring is a lift-off pin which projects through a bore, running from the rear side of the rack in the region of the toothing of the latter, into a tooth space and, in the position corresponding to the starting position of the carriage, is displaced by a tooth of the toothed segment with the desired effect of lifting off the leaf spring.
In order to ensure that the clamping device is closed before the carriage is moved into the printer, the pivoting shaft carrying the toothed quadrants is longitudinally displaceable. Before the transport movement of the carriage commences, the pivoting shaft is pushed so far to the side by a cam disk that the lift-off pin is released. The shaft is pushed into its original position again only when the toothed quadrant no longer comes into engagement with the tooth space containing the lift-off pin.
The known device is highly complicated in terms of construction, since several movable control elements have to interact at various points in the device.